Infusions remain ubiquitous in healthcare, spanning a wide range of conditions, substances, access sites and venues. Despite advances in oral and other drug delivery modes (e.g. transdermal, inhaled) many critical therapies still require intravenous (IV) infusion. It is estimated that one million infusions are administered per day in the United States. Over 90% of hospitalized patients receive an IV infusion.
Infused substances may include drugs (e.g. antibiotics, chemotherapy, pain medications, local anesthetics, vasoactive agents, biologics), fluids (e.g. crystalloids, colloids, parenteral nutrition) and blood products (e.g. red cells, plasma, platelets). These substances are typically infused as a single bolus volume (a few milliliters to several liters) over a limited time period (minutes to hours) or a continuous infusion delivered a fixed or titrated rate (typical range 0.05 ml to 5 ml per minute) over a more prolonged time period (hours to days).
Infusions may be administered through a variety of routes, most commonly intravenous but also intraarterial, subcutaneous, intrapleural, intraarticular, epidural and intrathecal. A wide variety of catheters and implantable ports are available to facilitate infusions in through these various routes.
Although infusions have traditionally been administered in hospital settings, an increasing number of patients are receiving infusions in ambulatory infusion centers and at home. Because these latter settings have fewer and less-skilled clinical personnel, only certain infusions are deemed to be safe to administer in such non-hospital settings including intravenous antibiotics, certain chemotherapeutic agents, local anesthetics for postoperative pain control and certain narcotic pain medications.
Current healthcare infusions technologies typically involve the use of gravity, active displacement electric pumps or non-electric disposable elastomeric pumps. However, there maybe certain disadvantages with these approaches. Gravity driven infusions have low capital and disposable costs but require careful monitoring by a nurse, can be inaccurate, can limit patient mobility, and have no patient safety features. Electric pumps are accurate (±3%) and have built in safety features of debatable efficacy but can be expensive, bulky, susceptible to human factors and have limited mobility. Disposable elastomeric pumps are convenient and fairly inexpensive, but oftentimes lack patient safety features, can be very inaccurate (±15-40%) and thus have little or no role in hospital based infusions.
The landmark 1999 Institute of Medicine report, “To Err is Human”, attributed 40-100,000 deaths per year in the U.S. to medical errors. Medication errors, 40% of which are serious, life-threatening or fatal, are the most common medical error and cost the health care system billions of dollars per year. Intravenous medication errors are the most common medication error and over 35% of these are related to infusion pumps. Studies have shown that despite progressively feature-laden “smart pumps,” human factors, software and hardware issues continue to contribute to serious errors. The FDA's MAUDE Adverse Event reporting system contain numerous examples of serious injury and death related to infusion pump errors, both electric and disposable. In the past four years over 600,000 electric infusion pumps from the two leading manufacturers have been recalled over major software and hardware problems leading patient injury and death.
The current state of healthcare infusions can thus be summarized as follows. Although hospital, ambulatory center and home infusions remain central to modern healthcare, infusion pump errors remain a major problem and contribute significantly to the large human and economic burden of medical errors. Electric infusion pumps have become expensive, high maintenance, complex technologic devices with well intentioned “smart” features of unclear benefit. Disposable infusion pumps have many attractive features but most are still inaccurate and may lack basic patient safety features making them inappropriate for most intravenous infusions.